I'll point out that the whole nudity around other guys being interpreted as gay attitude hasn't always been around. Before the rampany homophobia due to the outbreak of AIDS (originally called GRID, or Gay Related Immuno Deficiency), it was actually more likely that you would be considered gay for NOT getting naked amongst your peers in areas where nudity was acceptable. It was thought that either you didn't want to show yourself getting an erection (which, by the way, was tolerated as normal) and so were ashamed of your body, or that you thought you were better than the other people.
It's kinda like that in Japan's culture as well. The sento (public bathhouse in Japanese) serves as a gathering place for those that work together. Employers and employees often relax together as equals after a hard days work, although this is less frequent due to improvements in Japanese housing giving more people private facilities.
In any case, if the guy was in his 50's he might have just been echoing those past points of view. Some people just like the liberating experience of being naked with other guys; it's not necessary for it to be sexual. If both people are comfortable in their own skin, it's actually a kind of bonding moment, and one that is being almost totally eliminated in the US.
Additionally, if you look at the codes of conduct for nudist resorts, harassment or sexual advances are typically frowned upon, to the point where some families have been banned from family nudist resorts because their teenaged sons were getting spontaneous erections.
I personally really dislike the move to have more and more privacy in areas like locker rooms and saunas. It's a result of self-consciousness and self-esteem problems, but partitioned showers, changing stalls in locker rooms, and mandatory swim suits in saunas reinforce these trains of reasoning, causing people to become even more self conscious. No one wants to be scoped out by anyone else, because they think that being hit on by a gay guy will somehow make them less of a man.
Seriously, women have been told for decades that all they need to say is "No". Why is it so hard for men to take the same advice?